Abstract
Purpose. To develop a methodology for constructing an optimal work schedule for a group of trucks and drivers, which provides a guaranteed solution to the problem of insufficient productivity of the truck fleet, on the one hand, and a reduction in the shortage of drivers in the case of using a variable method of their work. At the same time, restrictions on the duration of work and rest of drivers are observed. The problem of low productivity is also manifested in the excessive duration of cargo delivery and too long downtime of trucks. Methodology. The optimal schedule of trucks and drivers was obtained as a result of solving the problems of synchronous routing of several vehicles according to the criterion of minimum mileage and establishing the moments of start/completion of transport and technological operations. These two problems were solved using an improved two-stage algorithm for ordering mixed directed graphs containing cycles. The general ordering algorithm includes linear programming methods at the first stage, as well as “divide and conquer” methods and auxiliary graph colouring at the second stage. Findings. A methodology for constructing an optimal work schedule for drivers and trucks has been developed, which allows for a variable work schedule for driver teams. A corresponding practical algorithm has been proposed. At the same time, the rules of the European Union regarding the work and rest regime of drivers have been observed. The total duration of cargo transportation is also reduced and the downtime of vehicles necessary for the rest of the drivers assigned to them is minimized. The effectiveness of the algorithm was tested on practical data from the activities of freight carriers. It was recorded that the duration of movement of trucks with cargo per day can be increased by 30.6 %. The overall productivity of trucks can be increased by 23.4 % without violating the European Agreement on the Work of Vehicle Crews. Originality. For the first time, the problems of routing road freight transportation and optimizing truck and car schedules have been solved synchronously. The tightest schedules of drivers of several vehicles were obtained in accordance with the norms of the European Agreement on the Work of Vehicle Crews on Complex Routes. Practical value. The developed methodology allows coordinating the operation of freight vehicles on the intercity transportation network, reducing their downtime, idling runs, and also reducing the time spent by driver teams when using the variable method.